Error checking

    mknod ${TAP_PATH} c $MAJOR $MINOR && : || ("ERROR: Cannot mknod: ${TAP_PATH}" && exit 20)

  fi

  exec 30>>$TAP_PATH

  exec 40>>/dev/vhost-net

  if ! exec 30>>$TAP_PATH; then

    echo "ERROR: Please add the following docker variable: --device-cgroup-rule='c ${MAJOR}:* rwm'" && exit 21

  fi

  if ! exec 40>>/dev/vhost-net; then

    echo "ERROR: Cannot find vhost! && exit 22 

  fi

  NET_OPTS="-netdev tap,id=hostnet0,vhost=on,vhostfd=40,fd=30"

}